The invention provides a light automobile driving axle assembly production line, comprising a differential sub-assembly assembly line, a main reducer-assembly assembly line, a main reducer assembly running test platform and a soundproof platform, a half-axle and brake sub-assembly assembly line and a driving axle assembly whole assembly line; the main reducer-assembly assembly line is an assemblyline with a closed ring which is formed by the circular connection of two sets of assembly clamp travelling pallet swap vehicles and a lifting machine; the lower end of the differential sub-assembly assembly line is connected with the upper end of the main reducer-assembly assembly line; the driving axle assembly whole assembly line is a subsequent assembly line which is assembled with the half-axle and brake sub-assembly connection after the differential sub-assembly is assembled with the main reducer assembly; the connection of line shift operation is carried out by a circular air transportvehicle. In the technical proposal of the invention, all the assembly lines have compact structure in the arrangement, smooth object-flow and operation shift and high assembly operation efficiency andcreates beneficial conditions for the matching and butt-assembly of the drive gears and driven gears in the drive gear pair and the driven gear pair of the main reducer assembly and for gaining online detection.